Erik's elevation is represented by the equation h = 12 – 0.75t, and raj's elevation is represented by h = 0.75t. what does the point of intersection on the graph represent?

The point of intersection between the height or elevation of Erik to that of Raj at a certain point in time, t is the distance in which they will meet. To determine this point, we get the value of h and t. 
                                     h = 12 - 0.75t
                                     h = 0.75t
Substituting the expression for h in the second equation to the expression in the first equation,
                                     h = 12 - h
                                      h = 6
 Get value of t, 
                                         6 = 0.75t    ; t = 8
Therefore, after 8 t's they will meet at an elevation of 6.